Video display systems have become almost universal with modern day computers with the advent of cheaper cathode ray display tubes and the availability of raster scan displays provided with the requisite control functions, buffer memories, etc., required for sophisticated display capabilities. These displays may be used with either small stand alone computers, or for large central systems having large numbers of physically distributed workstations. As is well understood, the video display is a convenient form of system monitor which may readily be employed for the purpose of controlling the operation of the computer by an operator having minimal experience in sophisticated computer operation areas such as programming. Thus, with menu driven types of systems a display appears on the screen with a plurality of possible actions or options from which the operator must choose. This choosing or selection can, of course, be done by typing alphanumeric inputs with a keyboard as is well known; however, in recent years selection by positioning a cursor in the display at the option or action of choice has been found to be far quicker and easier to use from an operator's point of view. Thus, the cursor controller display is becoming increasingly important as a means of controlling the computer both in the area of text processing and also in the field of computer aided design and drafting systems where rapid movement and precise final location of the cursor is important.
Originally cursors were moved almost exclusively by means of up, down, right, left keys on a keyboard, but it has been found that a much more versatile type of cursor movement is possible with the mouse type of input device.
The mouse, as generally known in the art, utilizes motion over a surface wherein a sensing means located within the mouse is utilized to detect motion and, in effect, produce incremental signals which are applied through a straight forward system interface to produce motion of the cursor in the X or Y direction on the display screen. Usually the mouse is shaped to fit conveniently in the hand of an operator sitting at a console table and is frequently provided with several function control keys such as shown in U.S. Pat. No. 4,550,316. The only way that the operator has of knowing where the cursor is located on the screen is by actually viewing the cursor as it moves across the screen.
Many different types of mice are available at this point in time. Each generates the required cursor control signals based primarily upon motion of the mouse across a surface (usually planar); however, the particular interaction of the mouse with the surface has traditionally taken a wide variety of forms. In a first type of mechanical pickup mouse, the mouse comprises a housing supported for rolling motion upon two wheels or sets of wheels which are disposed at right angles to each other. Thus, as the mouse is moved across the surface the respective wheels will either roll or slide depending upon the direction of the motion of the mouse. The rotation of the wheels causes X-Y displacement signals to be produced and sent to the video display system. The signals are translated into movement of the cursor.
In a second type of mechanical mouse the wheels are replaced by a single sphere which contacts the surface on which the mouse is to move and two wheels or sets of wheels are located internally of the mouse which are in intimate contact with the sphere and translate the motion of the sphere into two quadrature X-Y signals which are similarly converted into electrical signals and utilized to control motion of the cursor on the screen. U.S. Pat. No. 3,892,963 of Hawley and U.S. Pat. No. 3,835,464 of Rider, respectively, disclose the two above described systems.
In other types of systems optical means have been utilized to produce the requisite motion signals as the mouse is moved across the surface and a light source and sensors, placed in various locations around the surface, pickup the motion of the mouse. Such a system is described in U.S. Pat. No. 4,364,035 of Kirch.
However, in all of the above described systems, the only feedback between the operator and the mouse is the visible feedback on the display screen wherein the operator watches the position of the cursor as mouse motion causes it to move across the display screen. It is believed that there is a need in this technical area for a mouse having a feedback means wherein a clearly recognizable indication is fed back to the mouse that is apparent to the operator when the movement of the mouse has caused the cursor "to arrive" at some predetermined position or neighborhood on the screen. Thus, in a menu type of system the feedback would indicate to the operator that he had correctly positioned the mouse in a selection square or box on the screen. Alternatively, if some sort of computer assisted design work were being done a "resistance to motion" feedback of the mouse would indicate, for example, that the cursor had reached a particular line or lines on the screen and that the cursor was precisely oriented with respect thereto. Such a functional capability would free the operator from having to continually watch the screen especially where it was necessary for him to be concurrently viewing something else such as a template on the planar surface or some other material necessary to the application at hand. No systems are currently available which provide for the generation of such resistance-to-motion feedback to the mouse which may be physically perceived by the user.
The expression "resistive feedback" as used herein means, any resistance-to-motion feedback signal to the mouse which produces a user discoverable resistance to the motion of the mouse.